The proposed research encompasses two major lines of investigation into the processing of vibrotactile patterns by the skin, which are united by the common thread of inquiry concerning the fine structure of sequences of spatiotemporal patterns. The major thrust of our research will examine the processes of acquisition and discrimination of vibrotactile patterns. These will be examined primarily within the context of reading (identifying and discriminating) patterns that are presented on dense array displays, including Opatacon, a reading machine for the blind, and the MTAC, a New ultradense array. We intend to determine the factors that predict success in tactile pattern recognition. An untrained population of observers will be tested both on measures of cutaneous sensitivity and on more complex pattern discrimination tasks, such as masking and letter recognition, as well as the ability to process streams of information such as words. We will examine stream processing using several modes of pattern presentation, expanding on pilot data we have already collected on static (tachistoscopic) displays. A second area of research will examine how cutaneous saltation, a tactile illusion discovered and extensively studied in this laboratory, is involved with the family of spatiotemporal illusions that include apparent movement, and the Tau and Kappa effects. We also intent to explore further the conditions under which the spatial frequency response of the skin might be improved by the temporal characteristics of displays using saltation. Preliminary data suggest that the temporal intervals define by serially- presented vibrotactile stimuli. Using the dense arrays available to us in this laboratory, we intend to examine the saltatory effect on several body sites manipulating parameters which have been shown to influence judgements of distance and extent on the skin. The results will have implications not only for basic measures of tactile sensitivity by also for the ability to process more complex sequentially-presented patterns. The include letter shapes as well as vibrotactile derivatives of acoustic waveforms or visual spatial relations, which are found in aids for blind or deaf persons.